2–3 hours

Renal

Class A—Non-Clinical use—and Schedule II—Clinical use (UK),
DEA Schedule II (USA), S8 (AU)

20%

oral, intramuscular, intravenous, subcutaneous, intranasal, rectal, sublingual, transmucosal, buccal, transdermal (experimental)

Oral: 30–35%, Intranasal: 52–58%

C

Hepatic

HCl: 333 mg/mL (20°C)